Just follow the instructions in the box below the two playing areas.  Begin by placing your ships in "Your Water" by right or left clicking the area where you want the ship to appear.  A left click will place the ship horizontally, and a right click will place it vertically.  Once you have all five ships placed, click on one of the boxes in the "Opponents Water" where you want to strike and then click.  A white dot will appear if you miss, and a red dot will appear if you strike a hit.  After you strike against the opponent, click again and the computer will then strike against you.   Continue until one of you has sunk all of your opponents ships!

NOTE:  The computer does play randomly.   I've won and lost many times.